1. Field of the Invention
The present invention relates to a dispatching system and a dispatching method, and is particularly relates to dispatching system and method that automatically dispatch wafers, or lots that includes several wafers with same product, into tools. Moreover, the invention provides operators an on-line dynamic dispatching and also provides dispatchers both a forecast dispatching list and an adjustable way to optimize dispatching result.
2. Description of the Prior Art
A typical method for manufacturing semiconductor integrated circuit devices may include more than hundred process steps, which are usually at least classified into following categories: photolithography, etching, implantation, diffusion, deposition and sputtering. Moreover, in a semiconductor manufacturing fabrication factory, not only various variety tools (machines) are used for these process steps but also number of each kind tool is numerous. Further, not only abundant wafers under processing but also different wafers usually correspond to different products. Therefore, numerous tools, various processes and abundant wafers must be properly managed, and then how to dispatch wafers, or lots that include several wafers with same output, into tools becomes a very important topic in handling manufacturing.
In practical factory, process steps are performed in sequence. It means that a succeeding process step is performed when preceding process steps are finished. Beside, same category of process steps are performed together for same tools are mutually required, even required materials and processes are different. Moreover, the basic dispatching rule is dispatching some pending wafers to be processed whenever some tools are available. However, owing to some facts such as one tool can be used to process wafers with different products, wafers with different products at least requires different materials, and required process times of different wafers are different. It is obvious that the basic dispatching rule is improperly and it is desired to develop an advanced is dispatch way to efficiently dispatch wafers.
In typical conventional dispatching method and system, wafers that preceding process steps are finished are stored in a lots bank and wait to be dispatched into various tools (machines). On the other hands, operators of tools process wafers by some tools that are available to process wafers. Further, except some pre-provided information about which wafer must be processed preferentially and which specific wafer must be processed by which specified tool, operators only rely on their experience and judgment to decide which wafer should be preferentially processed and which available tool is used to process wafers. As can be expected, the conventional method and system often causes inefficient use of these tools. Moreover, because operators mainly dispatch wafers by their experience, whenever wafers with new product are appeared or new process are appeared or new tool are available, a trial duration is required. Beside, because stored wafers are manual dispatched by operators, it is impossible to precisely forecast both degree of progress of each product and insufficiency of required materials.
In short, conventional dispatching method is manual and off-line or conventional semiconductor wafer manufacturing line and then on-line dynamic dispatching wafers into properly tools is not possible. Further, conventional dispatching system is not adaptive for it can not precisely forecast progress of the semiconductor wafer manufacturing line, and then it is difficult to properly adjust degree of progress of different product and to timely supply required materials. Therefore, it is desired to develop method and system to automatically real-time dispatched wafers into properly tools and precisely forecast progress of the semiconductor wafer manufacturing line.
One primary object of the invention is to reduce the risk of dispatch, both in lateness and inadequate quantity.
Another object of the invention is to reduce the cycle time and maximizes output.
A further object of the invention is to provide operators of tools an on-line dynamic dispatch way that does not rely on the subjective experience and judgment of human operators.
Still a further object of the invention is to provide an off-line dispatching simulation to provide dispatcher a forecast dispatching list about dispatch of production line and a warning list about both lack of materials and idle tools.
Objects of the invention also include automatically dispatch wafers (lots) and timely modifying dispatching priority of all wafers (lots).
In accordance with this invention, a method for dispatching wafers that fabricated in a department of factory is disclosed. The present method comprises following steps: Determines a rank list of numerous wafers, wherein the rank list is sorted by numerous priorities of wafers and each wafer is corresponding to an individual priority. Herein, these priorities are automatically calculated with numerous system variables that modified by a dispatcher. Then, receives a limitation database that limits numerous relations between these wafers and some tools. Herein, the limitation database comprises information about an exception rule and information about each wafer is belonged to a super hot run, a hot run, a rush run or a normal run. Moreover, the limitation database is provided by the dispatcher. Finally, dispatches wafers into tools automatically in accordance with the rank list and the limitation database.
In accordance with the invention, a system for processing numerous lots by some tools with automatic dispatch is present. The present system comprises numerous tools, a lots bank and a controller. Herein, each tool is configured to perform a succeeding process on a batch of lots, the lots bank are configured to store numerous lots, and the controller are coupled to these tools and the lots bank. Further, the controller is configured to automatically dispatch these lots into these tools in accordance with a limitation database and a priority database. The limitation database is provided by a dispatcher and, comprises information about a exception rule and information that is used to identify each of lots is belonged to a super hot run, a hot run, a rush run or a normal run. The priority database provides each lot an individual priority that is automatically calculated before the lot is dispatched, where several adaptable system variables are used to calculate these individual priorities.
Also in accordance with the invention, a system for dispatching wafers into tools is disclosed. The disclosed system comprises determining means, receiving means and dispatching means. Determining means is used to determine a rank list of numerous wafers, wherein the rank list is sorted by priorities of all wafers. Further, individual priority of each wafer is automatically calculated with some system variables that are modified by the dispatcher. Receiving means is used to receive a limitation database that is used to limit numerous relations between wafers and tools. Moreover, the limitation database comprises information about a exception rule and information that is used to identify each wafer is belonged to a super hot run, a hot run, a rush run or a normal run. Dispatching means is used to automatically dispatch wafers into tools in accordance with both the limitation base and the rank list.